Study of the Low-Temperature Reaction Between CO and O2 over Pd and Pt Surfaces Full article
Conference |
Advances in Understanding and Application of Catalysts : Russian-American Seminar 27-30 May 2003 , Moscow |
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Journal |
Topics in Catalysis
ISSN: 1022-5528 , E-ISSN: 1572-9028 |
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Output data | Year: 2005, Volume: 32, Number: 1-2, Pages: 17-28 Pages count : 12 DOI: 10.1007/s11244-005-9255-2 | ||||
Tags | Atomic oxygen, CO oxidation, subsurface oxygen, Field electron microscopy, Kinetic oscillations, Molecular beams, Pd(110), Pd(111), Pt(100), Surface reconstruction | ||||
Authors |
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Affiliations |
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Funding (3)
1 | Russian Foundation for Basic Research | 02-03-32568 |
2 | Russian Foundation for Basic Research | 03-03-89013 |
3 | Los Alamos National Laboratory |
Abstract:
Field electron microscopy (FEM), high-resolution electron energy loss spectroscopy (HREELS), molecular beams (MB) and temperature-programmed reaction (TPR) have been applied to the study of the kinetics of CO oxidation at low temperature, and to determine the roles of subsurface atomic oxygen (Osub) and surface reconstruction in self-oscillatory phenomena, on Pd(111), Pd(110) and Pt(100) single crystals and on Pd and Pt tip surfaces. It was found that high local concentrations of adsorbed CO during the transition from a Pt(100)-hex reconstructed surface to the unreconstructed 11 phase apparently prevents oxygen atoms from occupying hollow sites on the surface, and leads to the appearance of a weakly bound active adsorbed atomic oxygen (Oads) state in an on-top or bridge position. It was also inferred that subsurface oxygen Osub on the Pd(110) surface may play an important role in the formation of new active sites for the weakly bound Oads atoms. Experiments with 18O isotope labeling clearly show that the weakly bound atomic oxygen is the active form of oxygen that reacts with CO to form CO2 at T 140–160 K. Sharp tips of Pd and Pt, several hundreds angstroms in diameter, were used to perform in situ investigations of dynamic surface processes. The principal conclusion from those studies was that non–linear reaction kinetics is not restricted to macroscopic planes since: (i) planes as small as 200 in diameter show the same non-linear kinetics as larger flat surfaces; (ii) regular waves appear under conditions leading to reaction rate oscillations; (iii) the propagation of reaction–diffusion waves involves the participation of different crystal nanoplanes via an effective coupling between adjacent planes.
Cite:
Gorodetskii V.V.
, Matveev A.V.
, Podgornov E.A.
, Zaera F.
Study of the Low-Temperature Reaction Between CO and O2 over Pd and Pt Surfaces
Topics in Catalysis. 2005. V.32. N1-2. P.17-28. DOI: 10.1007/s11244-005-9255-2 WOS Scopus РИНЦ
Study of the Low-Temperature Reaction Between CO and O2 over Pd and Pt Surfaces
Topics in Catalysis. 2005. V.32. N1-2. P.17-28. DOI: 10.1007/s11244-005-9255-2 WOS Scopus РИНЦ
Dates:
Published print: | Feb 1, 2005 |
Identifiers:
Web of science | WOS:000226939900003 |
Scopus | 2-s2.0-13844272167 |
Elibrary | 13485514 |
Chemical Abstracts | 2005:89740 |
Chemical Abstracts (print) | 142:285941 |
OpenAlex | W2082214949 |